In a nationwide speech as voting got under way, Correa told voters referendums are democracy's most radical process. His critics say his goals in Saturday's vote are undemocratic.

The plebiscite was considered an important gauge of popularity for Correa, who was first elected in 2006 and re-elected in 2009 after a rewrite of the constitution.

Some of the ballot questions are straightforward, such as whether bullfighting and gambling be banned. Others are quite complex. Each requires a separate vote.

Two of the most controversial questions would bar news media owners from other commercial interests and create a government media oversight authority.

Critics say both would make it easier for Correa, who is often at loggerheads with the largely opposition news media, to subtly impose censorship.

Correa is a close ally of President Hugo Chavez of Venezuela firmly established in South America's leftist bloc. He enjoys a 65 percent approval rating in a country that in the decade prior to his election saw three presidents ousted in popular revolts.

Correa has alienated much of the business community and even former allies, including leaders of Ecuador's indigenous movement, who are angry with his insistence that the state have the last word on subsoil and water rights.

But Correa's populist programs, such as $35 monthly payments to nearly 2 million poor families, construction of low-income housing and a commitment to universal free education, have boosted his popularity in this small Andean nation of 14.3 million people.

Political analyst Adrian Bonilla of the FLACSO think tank says that with strong leadership, Correa has ably leveraged Ecuador's oil wealth and an effective tax regime into popular programs.

He has drawn criticism for alleged autocratic tendencies, however. Former President Osvaldo Hurtado, a conservative opponent from the Christian Democratic party, says Correa has conjured "a perfect dictatorship" by manipulating democratic institutions much as many say Chavez has in Venezuela.

Correa has alienated many foreign investors by renegotiating oil contracts to give Ecuador a higher cut of windfall profits, and has forged new business ties with China and Iran.

Last month, he expelled U.S. Ambassador Heather Hodges after the anti-secrecy website WikiLeaks disclosed a diplomatic cable she penned suggesting Correa was well aware but tolerant of high-level corruption in Ecuador's national police. Correa denied the allegation.

One of the most important ballot questions would dissolve Ecuador's judicial oversight council, replacing it with a temporary body charged with reforming the system. Another would allow authorities to detain people for longer without filing charges.

Polls indicated before Saturday's vote that about half of Ecuadoreans were having trouble understanding the ballot questions.

Many voted "no" as a result.

"The truth is I don't understand a lot of the questions," said Nataly Mendez, a 24-year-old pharmaceutical representative voting in Quito's lower-middle-class Don Bosco neighborhood. "That's why I voted no."

Many who voted "yes" indicated it was because they esteemed the government.

"We Ecuadoreans should be committed and help out if we want things to change," said Maria Lourdes Silva, a 43-year-old cosmetics saleswoman.